Designing an IoT Device: Tradeoffs Abound, Many Ugly

“There’s no Internet-enabled device I’ve made that I would give to a non-geek friend,” said embedded software engineer Elecia White, speaking today at the Embedded Systems Conference at EE Live!

The 100+ audience consisted of a mix of hardware, software, and firmware engineers, plus one marketing guy who cleverly showed up to hear an engineer’s candid critique of his profession.

“I feel lied to,” said White, who operates the consulting company Logical Elegance. She has implemented code and worked on hardware for several connected devices, including a WiFi scale and a Bluetooth robotic exoskeleton. But based on her first-hand experiences, she’s concluded that today’s Internet of Things is still too unreliable, difficult-to-use, unconfigurable, insecure, and can cause users unnecessary frustration.

White’s advice? Don’t believe every marketing pitch about the IoT. And focus on working through the myriad device tradeoffs with the express purpose of creating happy customers.

And if you can’t make your customers happy, at least don’t make them unhappy.

Consumers need your product to work right out of the box, she said. “Users are most frustrated with the configuration step. If they turn it on and feel stupid right away, they are never going to get the opportunity to love your product, no matter how great it may be.”

The tradeoffs encountered in designing a product for the Internet of Things run the gamut from selecting a connection option to managing firmware updates. Unfortunately, there are few choices that don’t include at least one ugly tradeoff. To wit, White says she has never picked a communication protocol that didn’t at some point make her wish that she had picked something else.

“You’re really burdening your customer when your choice is a power hog, but on the other hand it’s pretty onerous to expect him to buy a server,” White said, comparing a modem to the proprietary network ANT.

To make matters worse, White pointed out that, because the cloud is far away from the typical embedded developer’s core skill set, there’s a need to learn new skills and computer languages.

While new solutions are coming out almost every day that can make connecting to the cloud easier for an embedded engineer, White pointed out an ugly tradeoff there, too: “I’m not so sure that I want them to have my server data. Or at least I want the option to get it back in the future if I want it.”

If I want to know if the milk's bad, one wiff will do it. The temperature offers little value I find milk good for 2-6 days past the used by date and that can be for 2 cartons bought on the same day with the same expiry date.

A fridge that tells me I'm out of milk tells me nothing I don't already know because I used it and what if I bought more fruit juice last week so there's a fruit juice in a milk slot?

I can't for the life of me figure out what I would want an internet connected fridge for (certainly not to browse the web), having a power meter tell me the power is out and therefore the fridge & freezer are off line maybe.

A toaster? well If I'm down the street when the toast is done I won't make it back in time to butter it.

I think control in plants is a good idea and having the power utilities all wired is great, but I just don't see many other actual useful uses for IoT.

Maybe I'm lacking imagination, but in a world where we need to reduce power consumption, adding an ethernet power hog to everything doesn't sound like a good idea.

Does anyone have a difinitive list of things that are going to be attached?

It sounds better for industrial uses but don't they already have sensors, networks, data, and analytical tools?

Agreed, Highlander. It has been around in non-consumer venues for decades, even if not always in a pure Internet Protocol form (e.g. there's a long transitional phase of other industrial network protocols connecting to sensors and devices, then gateways tied together with IP). That's why I've never understood the hype.

1. I'm worried about the weight impacting on expected performance/balance/spin. Basketballs have fairly low mass and are sensitive to such things. The illumination has got to require a sizeable battery and wireless transmission over the required distances too.

2. Data gathering This is a boon to people wanting to sell something, but generally not to endusers. for cooking I see a tablet with a skype like program a better investment. Fitness we already have the ability to download the data to a PC. an IoT version will not have the battery life of current devices. Using an NFC connection to a mobile phone would make more sense and reduce battery size/consumption.

3. definitely worthwhile for some things, a car maybe, most household appliances have near zero maintenance. The only thing I have that might benefit is my coffee machine that already puts up a display to descale or whatever when I'm within reach of it and can actually perform the task. If I was away I wouldn't beable to do much with the message and I certainly wouldn't want it calling the serviceman to do a descale. I've repaired my dryer 4 times in the last 30 years, twice for a belt, once for a thermaostat and once for a broken switch. If it had an IoT board you could add 3 times to have a faulty logic board replaced if my dishwasher is anything to go by. Outside the home in mining etc. there would be a big call for it but that's the industrial arena where it'a already being done extensively.

4. This one is an interesting thought although I'm not sure it offers additional utility to existing methods.

5. I've added this one :-) vending machines would benefit but that's more an industrial/commercial use.

One guy that works on automation of cooking is a very famous product design expert(forgot his name). So it could be a great popular product. It's too early to tell how future kitchen will look.

> Fitness we already have the ability to download the data to a PC. an IoT version will not have the battery life of current devices.

People preferer that stuff done automatically - the data automatically downloaded to net, automatically analyzed, possibley with automatic relevant notifications. And as for the complexity of charging - there's wireless power. Just put the watch in intel's wireless power bowl.

> Predictive maintenence

You're lucky to have a dryer that lasts 30 years. Most of the stuff sold is not very reliable. And most control boards are electronic.

Thanks for your feedback, I'm interested in how it pans out. I'll be watching that space.

> Dryer

Yeah I'm an electronics design engineer so I buy things that are as unelectronic as possible :-) That's why they last so long. Amazing how reliable 2 bi-metal switches an electromechanical selector switch a polyurethane drive belt and an AC brushless motor can be.

I have a fridge that's 32 years old too where the traditional thermostat sensor tube leaked due to corrosion after 19 years only because it was assembled wrong in the plant. The new one I put in will out-live the compressor.

Our hotplate is electric with bimetal thermostats so after 12 years in this house it's still going.

Pity the Chinese don't know how to make oven elements or I wouldn't have had to change 2 in 12 years in our oven. Our old one made it to 30 years when we moved and was still going.

Most stuff I design has a 30-40 year lifespan but redesigning controllers for all the new products I buy is obviously not an option so low tech it is (where possible).